Buggy code:
public class MainActivity extends StandAppBaseActionBarActivity implements ViewPager . OnPageChangeListener , UserInfoListener , OnFragmentCreatedListener , GCMHelperListener { private static final int REQUEST_OAUTH = 1 ; private static final String AUTH_PENDING = "auth_state_pending" ; public static final String INTENT_PARAM_USER_EMAIL = "USER_EMAIL" ; private static final String SELECTED_TAB_INDEX = "SELECTED_TAB_INDEX" ; private boolean authInProgress = false ; @ InjectView ( id . tabs ) PagerSlidingTabStrip tabs ; @ InjectView ( id . pager ) ViewPager pager ; @ InjectView ( id . content ) LinearLayout content ; @ InjectView ( id . progressBar ) ProgressBar progressBar ; @ Inject GooglePlayServicesHelper googlePlayServicesHelper ; @ Inject GoogleFitAPIHelper googleFitAPIHelper ; @ Inject UserHelper userHelper ; @ Inject GCMHelper gcmHelper ; @ Inject UserInfo userInfo ; @ Inject UserInfoMediator userInfoMediator ; @ Inject PreferenceAccess preferenceAccess ; private int numAsyncSuccessfullCallbacks = 0 ; @ Override public void onCreate ( Bundle savedInstanceState ) { } private void initToolbar ( ) { } @ Override public boolean onCreateOptionsMenu ( Menu menu ) { } @ Override public boolean onOptionsItemSelected ( MenuItem item ) { } private boolean goToSettings ( ) { } private boolean goToWebsite ( ) { } private ConnectionCallbacks connectionCallbacks = new GoogleApiClient . ConnectionCallbacks ( ) { @ Override public void onConnected ( Bundle bundle ) { } @ Override public void onConnectionSuspended ( int i ) { } } ; private void subscribeToStepsIfFirstTime ( ) { } private void subscribe ( final DataType dataType ) { } private void initFragments ( ) { } private OnConnectionFailedListener onConnectionFailedListener = new GoogleApiClient . OnConnectionFailedListener ( ) { @ Override public void onConnectionFailed ( ConnectionResult result ) { } } ; private void logMsg ( String msg ) { } @ Override protected void onResume ( ) { } @ Override protected void onStart ( ) { } @ Override protected void onStop ( ) { } @ Override protected void onActivityResult ( int requestCode , int resultCode , Intent data ) { } @ Override protected void onSaveInstanceState ( Bundle outState ) { } @ Override protected void onDestroy ( ) { } @ Override public void onRegisterSuccess ( String regId ) { } @ Override public void onRegisterFailure ( String regId ) { } @ Override public void onRequestSent ( String regId ) { } @ Override public void onRequestNotSent ( String regId ) { } private void startGenericErrorActivity ( ) { } @ Override public void onAlreadyRegistered ( String regId ) { } @ Override public void onUserRefreshed ( User user ) { } @ Override public void onEmailMissing ( String userEmail ) { } @ Override public void onUserNotFound ( String userEmail ) { } @ Override public void onNetworkError ( ) { } private void startChromeExtensionErrorActivity ( String userEmail ) { } private void replaceThisActivity ( Intent intent ) { } @ Override public void onFragmentCreated ( ) { String userAccount = preferenceAccess . getUserAccount ( ) ; <START_BUG> if ( ( ! ( userAccount . isEmpty ( ) ) ) && ( ( userInfo . getUser ( ) ) == null ) ) { <END_BUG> progressBar . setVisibility ( VISIBLE ) ; userHelper . refreshUser ( userAccount ) ; } } private boolean refreshUser ( ) { } @ Override public void onPageScrolled ( int position , float positionOffset , int positionOffsetPixels ) { } @ Override public void onPageSelected ( int position ) { } @ Override public void onPageScrollStateChanged ( int state ) { } }

Fix:
if ( ! ( userAccount . isEmpty ( ) ) ) {